A.M.
My feet also tend to crack really badly, and I swear by Heel Rescue. Their foot cream is a bit too thick for everyday use (IMO - I just use Eucerin every day) but the repair kit (a small intense hydrating lotion container and a pair of socks to sleep in) works wonders if you forget to lotion for a few days. I found it at HEB, but you can probably find it anywhere.